In order to find utilization patterns, one is looking for repeating isomorphic subgraphs with the same utilization values assigned to all subgraph nodes. Such subgraphs encode class-specific parts in traffic sign classes, for example, several rotated curvatures in round shaped traffic signs using curve detectors [1]} in mono-semantic subgraphs or multiple spatial- and intensity-based traffic sign characteristics in poly-semantic subgraphs. We hypothesize that a presence of physically realizable trojans will perturb utilization patterns.
